Jet Stream Tattered By Climate Change Brings New Bout of Worst Storms On Record For North-Central US


(Mangled Jet Stream on June 20th, 2014 together with cut-off upper air low threatens record-shattering storms and flood events across a multi-state region from the Dakotas to Minnesota to Iowa and Nebraska over the coming days. Image source: Earth Nullschool. Data source: NOAA.)

If you wanted an example of a Jet Stream mangled by human-caused climate change, you couldn’t find a better one than today’s tangle of upper level winds swirling over North America.

It’s a chaotic maelstrom of split flows, colliding storm tracks, blocking highs, and cut-off upper air lows. A barrel of snakes pattern that’s become ever-more-common since Arctic sea ice plummeted to staggering volume lows of nearly 80 percent less than 1979 levels at end summer of 2012. A loss that opened wide the gates for warm air to flood northward and confuse the hot-cold dividing line that drives this key weather governor.

Over the past week, we’ve seen what amounts to a mess of storms mostly locked in place. A Pacific Ocean flow squeezed between a blocking high off California and an upper level low south of Alaska drew a train of moisture trailing all the way across the Pacific into a hungry cut-off low that had stalled along the border between Canada and the US. Drifting slowly east to west, west to east, the low gorged on the synoptic moisture feed, dumping record rainfall after record rainfall over the Dakotas, Minnesota, Nebraska and Iowa.

100 Year Records Shattered

By the 16th of June, with just slightly more than half the month passed, Sioux Falls South Dakota had crushed its all-time record rainfall for any month by more than 2.5 inches. The previous record of 9.42 inches set in 1898 catapulting to a staggering 13.04 inches by early this week. And with the storm track writhing overhead the rains for the region just kept coming. By yesterday, the twin cities region in Minnesota had rocketed to its second wettest June on record amidst massive rainfall-driven landslides and region-wide preparations for Mississippi River flooding. At 10.33 inches measured rainfall so far, with storms still popping overhead, and with 11 days still remaining in the month, it appears the area may well be set to shatter the previous rainfall record of 11.67 inches set back in 1874.

(Record flooding along the Big Sioux River in Iowa and South Dakota as witnessed yesterday by Storm Chasers.)

All the massive rainfall has built up quite a pulse of flood water that is now moving down major river systems and threatens record flooding events throughout a multi-state region from the Dakotas to Minnesota to Iowa to Nebraska. Residents are being called to aid in sand bagging and other flood mitigation operations as rivers keep rising through numerous regions. According to a report today in the Christian Science Monitor:

“In Iowa, South Dakota, and Nebraska, officials are asking volunteers to build sandbag barriers and other fortifications in advance of the brunt of the storm – but politicians and emergency workers are conceding that their efforts, in some areas, may not be enough.

In South Dakota, workers have begun turning a major Interstate exchange bridge into a temporary levee. While officials there say that will mitigate the flood in many locales, Governor Dennis Daugaard (R) said he expects parts of North Sioux City, S.D., to be underwater by the end of the week.”

Storms Expected to Continue

Today a frontal boundary sweeping out from our upper air low is bringing rains to the Great Lakes and Central Plains region. Meanwhile, behind the front, instability and moisture flow beneath the low continue to result is a high risk for severe thunderstorms accompanied by strong winds, torrential downpours, hail and frequent lightning. Severe storm risks are most extreme for areas of southeastern Nebraska, western Iowa, northern and western Minnesota, and eastern North Dakota.

Already, satellite imagery shows strong storms and accompanying high cloud tops popping up over Nebraska with more likely to follow as afternoon and evening progresses.

Conditions in Context: How Climate Change Intensifies Droughts/Storms

Multiple news agencies are now gathering reports of record storm events throughout the affected multi-state region. Recording agencies and residents alike note a dramatic increase in both the frequency of record events and in their intensity.

Storm precipitation intensity is a measure of how much rain, snow, sleet or hail falls from a given storm over a given period. And what we have seen is an increasing number of record hourly rainfall events in which precipitation totals measure 1 to 2 inches or more within a 60 minute span. Such intense events rapidly overwhelm infrastructure, flood roads, and burst river banks, creating a dangerous situation that often results in numerous water rescues. And both local and national climate reports have marked a major increase in both precipitation and precipitation intensity over the past two decades for regions such as Iowa.

In the context of human-caused climate change, frequency of intense storm events is increased due to rising atmospheric moisture loading. Overall, for each 1 degree C increase in temperature, the hydrological cycle increases by about 7% in intensity. The current .8 C rise since 1880 has resulted in about a 6% increase in the rate of evaporation and of rainfall. So in regions where heat and dryness tend to take hold, the soils tend to dry out faster, tipping into drought conditions far more rapidly and seeing an overall intensification and lengthening of droughts. And in regions where storms do form, they tend to dump far more rainfall than they used to.


(Global warming intensifies thunderstorms by adding convective energy, increasing atmospheric moisture, and expanding the troposphere. As a result, thunderstorm cloud heights increase resulting in more intense rain and hail events. Image source: National Weather Service.)

Changes in the Jet Stream due to loss of sea ice in the Northern Hemisphere also tends to result in more persistent weather patterns. The Jet Stream tends to meander more, spinning off more cut off lows that linger over regions creating instability and rough weather for longer periods. High amplitude waves tend to also form as more warm air invades the higher Latitudes. In the ridges, powerful high pressures tend to dominate. And once these highs establish, they can be very difficult to move. Beneath these blocking highs, droughts proliferate due to the extreme length of dry periods and due to the intensified rate of evaporation. We see such an event now in the 15+ month long blocking high that has so greatly impacted California and the ongoing drought there.

Lastly, increasing convection and a thickening, hotter atmosphere tend to spike storm intensity. In areas where moisture and heat are both high, the explosive rate of evaporation tends to rapidly form storms with very high cloud tops. These cloud tops, now sometimes pushing 50,000 or 60,000 feet pack in more moisture and can generate very intense rainfall events over shorter periods than we are used to.

In these ways, climate change forms an ideal brew for perfect thunderstorms and perfect droughts. With temperatures expected to spike to +2 C or great anomalies over the coming century, we can look forward to extreme weather continuing to intensify with both record rainfalls and record droughts dominating with ever-increasing frequency.




Weather Underground: Record Rainfall in Sioux Falls South Dakota

Twin Cities: Flood Preparation Begins as Record Rainfall Sends Mississippi Rising

Global Warming to Spawn More Severe Thunderstorms

Warming Planet Could Spawn Bigger, Badder Thunderstorms

How Climate Change Wrecks the Jet Stream, Amps up the Hydrological Cycle and Spawns Severe Weather

Hat Tip to Colorado Bob

Hat Tip to TodaysGuestis


Leave a comment


  1. Small point perhaps, but the address visible in the first image is to a dynamic graph similar to the image itself, but one that shows wind, temperature, relative humidity, atmospheric density, wind power density, total precipitable water, total cloud water, and mean sea level pressure at different heights, using colored scales with and numerical values available by mousing over the scale, all which can be represented using any one of eight different projections. You can view the available actual and forecast data for different time periods according to 3 hour increments. Ocean data is available as well.

    Please see:

    Click “earth” in the lower left corner for the menu…


  2. Spike

     /  June 20, 2014

    This reminded me of a terrific summary of current impacts of anthropogenic climate chaos here:


  3. Excellent talk by Kevin Trenberth

    Extreme weather and its links to climate change


  4. colinc

     /  June 21, 2014

    From the caption of the bottom-most image in Robert’s post…

    Global warming intensifies thunderstorms by adding convective energy, increasing atmospheric moisture, and expanding the troposphere.

    This is something that has been on my mind for some time and I am unable to find any relevant information/papers/comments regarding my conundrum. By noting the “expanding… troposphere“, what are you really saying? In other words, is the troposphere becoming “thicker/higher?” Or, perhaps, it is becoming more “dense?” Is that leading to greater atmospheric pressure at “sea-level” (STP)? Is it “contributing” to increasing temperatures? Is the stratosphere becoming “thinner” or is it being “pushed” further into “space?” Given the latter, will this not increase “drag” on orbiting “junk?” If “none of the above,” which, if any, atmospheric components/molecules are being “displaced,” which ones and by what “mechanism?” What are the impacts/ramifications of any of the preceding queries? In yet more other words, we keep adding CO2 & CH4 to the atmosphere and in “response” the atmosphere “automagically” adds more water vapor, the “equation” (alleged “equilibrium”?) appears to be unbalanced! Or in other, other words, even when a “chunk” of pure Na is immersed in H20, the “exciting” changes and dramatic end result can be expressed in balanced equations on a moment to moment basis. WTF is the atmosphere really doing?

    Rephrasing all of the previous paragraph…
    If we presume the atmosphere and the planet as similar to a “balloon” encompassing some “gas” surrounding a solid orb, then said “orb” releases a significant amount of “gas” while “maintaining” its own volume, what happens to the gas-density or the overall balloon volume?
    Are my questions/thoughts making any “sense” or have I once again had too much bourbon? (Is there really anything like “too much” bourbon? Well, besides too much THC? No, wait, scratch that last query as irrelevant!) 😉


    • Colinc, your point: “If we presume the atmosphere and the planet as similar to a “balloon” encompassing some “gas” surrounding a solid orb, then said “orb” releases a significant amount of “gas” while “maintaining” its own volume, what happens to the gas-density or the overall balloon volume?” Seems to describe quite well the basic physics at work here. Just tasking to illustrate the most simple processes seem to take the greatest effort. I seem to remember some declaring that the amount of O2 in the atmosphere is on the decline — maybe in ratio to other gases and aerosols? Either way our atmosphere is being overwhelmed by substances other than its historical components or those that are life sustaining.
      Thanks for your illustrative comment.


    • A good place to start…

      Use Google fu on global warming + Hadley cells.

      Then turn that same Google fu onto sudden stratosphere warming (SSW).

      Then, for fun and just to scare the living day lights out of yourself google wet stratosphere.

      The various related references should provide food for thought (a glass o might help smooth it all out).


      • colinc

         /  June 21, 2014

        “Google fu”? Is that some “subset” of Google or are your implying something else? I did find it “interesting” that merely searching for “wet stratosphere” in Google required the addition of “-samsung -hotel” to get results of any relevance. While the few that I read/scanned indicated more water vapor in the stratosphere was contributing to a decrease in ozone (implying increasing UV down here on the surface?), I didn’t see anything particularly scary. However, perhaps I haven’t yet read enough.

        I’ve gleaned a fair amount of understanding regarding SSWs and the changes in Hadley (and Ferrel and Polar) cells from the discussions on the ASIB the past couple of years but the results from your first search suggestion were quite interesting. So, regardless of any other implications, intended or not, thanks.


        • Wet stratosphere is the first step toward a Venus-like climate resulting from extreme warming and troposphere expansion. May want to google wet stratosphere + James Hansen.

          Google fu is a tongue in cheek term for internet research skill.

          In general, the heat + water vapor feedback expands the troposphere, but it tends to occur first in certain regions. SSW events are temporary teleconnections in which an expanding troposphere transfers heat energy directly through the stratosphere and on to the polar zone. The dynamics that expand the troposphere, alter Hadley Cell range, and set off SSW events are similar and so they are worth looking at together in context. It’s also worth looking at recent research into a zone of elevated troposphere over the western equatorial Pacific.


      • colinc

         /  June 21, 2014

        That is a fascinating paper! So, the tropopause seems to be increasing in height implying that the troposphere is becoming “deeper” but I didn’t see anything indicating whether the stratosphere was getting “narrower” (vertically) or being “pushed” outward. Would this not also imply that atmospheric pressure at the Earth’s surface is increasing, albeit “minutely?”

        I’ll have to cogitate further on this and the preceding info but, especially in light of the decreasing O2 concentration (from Scripps), the implication seems to be that the atmosphere may also be becoming thicker/denser/more viscous(?)! Nonetheless, thanks again.


        • Yes, atmospheric pressure rises over time as under warming the atmosphere accumulates more material. Likely the strongest initial contributor to increasing pressure is water vapor. Overall, though, pressure increases would be rather minor compared to other physical changes. A greatly increased atmospheric pressure would arise from very extreme changes to the Earth system and such extremes would have long since removed an atmospheric state capable of supporting life.


  5. The jet stream image is telling.


    • pintada

       /  June 21, 2014

      Apparently, the term “jet” stream is loosing its meaning. Perhaps “blocked stream”, “meandering stream”, “random flow”?

      There is significant evidence that there was no jet stream during the eocene.


      • Older men often experience “weak flows” and “blocked streams” due to benign prostatic hyperplasia (BPH). Perhaps an analogous condition should be attributed to this climatic phenomenon such as “malignant tropopausal hyperplasia” (MTH)… or, “Man the Temperature is getting Hot!”


      • If the temp differential between high and low latitudes falls enough, that’s generally what you’d end up with. Pretty stagnant conditions.


  6. Ali

     /  June 21, 2014

    Dear Robert; what is your position on nuclear energy?
    thanks in advance for your honest answer.


    • Nuclear has proved to be hazardous again and again despite assurances. The current tech results in toxic materials that are problematic to store and result in risk of nuclear weapons proliferation. Construction costs are extraordinarily high and the energy expense is greater than that of renewables. I tend to favor renewables over nuclear but do not support shutting down current nuclear operations if those plants are to be replaced by coal or natural gas. At this point, I believe the accumulation of ghg is currently at existential threat levels, especially when you consider the time scales involving energy infrastructure construction and replacement. So my view is that shutting down fossil fuel plants should take top priority with an exclusive preference to replace such plants with increasingly less expensive and far less dangerous renewables.

      In general, though, I recognize the danger represented by current nuclear plants and tend to believe that safety plans are overly optimistic and do not take into account the risks posed by out of context events. There are a number of interesting potential nuclear technologies that, at first blush, appear somewhat less dangerous and potentially very abundant energy sources. However, I remain rationally cautious regarding new tech claims — RE safety, availability, energy production and price — as the tendency has been to over-promise.

      So, overall, my first focus is on the reduction and elimination of fossil fuel use, but with a healthy understanding and concern for the very real risks posed by nuclear. Lastly, the qualitative value of the threat posed by nuclear, at this point, is one I consider to be less than that posed by climate change. This is not to downplay the nuclear hazard, which is a very real risk. But to emphasize how dangerous the use of fossil fuels has now become.

      Finally, I think is is important to keep each crisis within its context and I believe the Fukushima crisis, though very damaging and harmful, has been blown well outside of its context by a combination of hysteria, bad thinking, and intentionally seeded misinformation. This is not at all meant to downplay valid concerns. But claiming, for example, that the Fukushima spill affects ocean temperatures, or that sea star wasting research is conspiring to cover up non-existent radiation exposure evidence is frankly ludicrous.


  7. Re: the visuals used in this post per my photographer’s eye. The YouTube still of the flooding Big Sioux River shows bright pasty white (no yellow or gold — definitely no “Kodachrome colors” possible here, a thing of the past in most daytime situations — digital or film) sun glare reflections on the water that I believe is indicative of an atmosphere that is dense with moisture and particulate.
    The lower third of the cloud top photo is thick with air pollution — that brown gray pollutant haze. The upper air appears quite clear.
    I have been bothered by this sort of thing (visibly polluted air) for a long time, and I wonder how the many photographers, and those working in video and film avoid it.
    Outdoor and natural available light is, to me, “off the charts”. Ansel Adams, I’m sure, would shake his head in contempt.


  8. Bee

     /  June 22, 2014

    I’ve been a regular reader of your blog for a while now and I very much appreciate how you explain and lay out what is going on weather-wise. If you don’t mind, I’d like to ask a question.

    I was recently in Dusseldorf, Germany for two weeks. While I was there, the area experienced an extreme wave of heat, about 34C. Then, on Mon June 9th, Dusseldorf experienced what was considered to be the worst storm that the area had seen in 20 years. I come from the American Midwest, so I’ve seen storms, but this storm scared me. The German news noted that it carried 93mph winds and the whole system caused a LOT of damage. I’m very curious to know how Global Warming is affecting Europe and if these sorts of storms are going to become more common. When I was there, the general conclusion was that this was nowhere near a normal thing and it greatly surprised the residents. I’ve heard a lot about the Americas and Asia, but I haven’t heard much on how Europe is being affected. I have friends and family there.

    Here are two articles on the storm:


    • Hello Bee, welcome, and thanks for posting.

      Up until that time, your region was under the influence of a broad ridge of high pressure extending out from the Caspian and over much of Eastern, Central, and a part of Western Europe. A trough spreading out over the Barents fed on the moisture spilling out from that ridge. Eventually the trough gained strength as cold air fled the Arctic, entering Northern and Western Europe. The ridge shifted west into Central Asia and a powerful storm swept through your region. Because the ridge persisted for so long, evaporative moisture loading into the trough was extreme. High temperature differentials increased instability, feeding more intensity to the storm. So as the trough swept in, you ended up with a powerful event. A 20 year storm.

      Now think of the intensity of the storm you witnessed and consider the fact that Serbia, to your southeast, saw what was likely a 1000 year event just weeks before. And we see 100 year events around the world with growing frequency. This winter, a series of very heavy storms pummeled the UK resulting in both the windiest and rainiest winter on record. It was an event I covered extensively here.

      With the Arctic so close, and with the North Atlantic undergoing radical change, Europe is on the front lines of what is bound to be an extraordinarily stormy conflict between building heat and the death throes of cold.

      James Hansen warned that storms would characterize the life spans of his children if we continued emitting greenhouse gasses. He wrote a book about it called ‘The Storms of My Grandchildren.’ Well Bee, it appears the storms of our grandchildren are arriving early.


      • Here in Norway the meteorologists are generally talking about not using 50-year, 100-year, Nth-year to label weather events as they have no meaning anymore due to the frequency of certain events. Hansen’s “Storms of my Grandchildren” is already “Storms of my children” in my eyes, and no doubt for those in the middle of life will get to experience a major shift in climate these coming decades as the Arctic ice disappears.

        However I don’t think all here grasp that increased precipitation covers both summer and winter for this part of the world (Scandinavia), so winters can have some serious snowfall as well – keeping the old “its cold outside, so where is global warming?” – meme alive for decades still. I guess that is why I generally say Climate Change from Anthropogenic Global Warming – so the link is more clear. But on average there will be more heat records shattered for every cold one, the cold records might not come in the dead of winter, but possibly in the middle of summer. This is what people need to realize – there is a new set of rules climate have to play by as the system heats up.


      • Bee

         /  June 23, 2014

        Thank you for the details. While I was there, I had no television or reliable internet access, so I had no idea what was coming or the weather systems that were in play. The heat and storms caught me completely by surprise. I try and keep track of what is going on in the United States, as I’ve always had a sort of love for meteorology. (I remember keeping a hurricane diary when I was in elementary school and watching the Weather Channel for hours on end) Needless to say, I’ve been horrified by what I’ve been seeing happen over the past decade.

        I remember reading about the UK and Serbia storms on your blog. It’s terrible, all of it. I have a daughter and I’m so upset at the world she might live in as she grows older. Like any other parent, I want her to have a happy life, but these storms, events, and records are starting to scare me as a parent and as a human. I’ll have to see if any local libraries have that book, it seems to have escaped from my radar.


  1. aporía/ el ártico se muere, del blog de antonio turiel | tratar de comprender, tratar de ayudar

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